E0-A | B | C-Cn | Co-Cz | D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
0-A | B | C-Cn | Co-Cz | D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
- E: Voltage (electromotive
- E-Mail: See Electronic Mail
The European equivalent to the North American T1 carrier trunk. E1 users a
2.048 Mbps transmission rate.
- Earth: British terminology for
- EBCDIC: See Extended Binary
Coded Decimal Interchange Code
- Echo: The name given to the ICMP
packets used to check the reachability of nodes or devices on a network system.
These packets are sometimes referred to a "Ping" packets.
See Entry Emulator High Level Language Applications
- EFF: See Electronic Frontier
- EGP: See Exterior Gateway
- EIA: See Electronics Industry
- EIA RS-455: The EIA “Standard Fiber Optic Test
Procedures for Optical Fibers, Cables, Transducers, Connecting & Termination
Devices”, RS-455 includes Fiber Optic Test Procedures (FOTP) for many of the
mechanical & optical requirements of optical fiber
- EIA/TIA-568: EIA/TIA-568A The
latest version of the “Commercial Building Telecommunications Wiring Standard”
which has become one of the dictating standards for copper & fiber
- EISA: See Extended Industry Standard
- Elastomer: Any material that will return to its
original dimensions after being stretched or distorted.
Closet: A floor-serving facility for housing electrical equipment, panel
boards & controls. The closet is the recognized interface between the
electrical backbone riser & its associated pathway.
Ground: One of four functions categories of DTE-DCE interface signals.
These signals provide common electrical points & discharge static & harmful
- Electromagnetic: Referring to the combined electric &
magnetic fields caused by electron motion through conductors.
- Electromagnetic Interference: (EMI) Refers to the
electrical & magnetic signals generated & transmitted by electronic &
electrical equipment. Electromagnetic signals from some sources are strong
enough to interfere with the proper operation of electronic equipment such as
net working devices.
- Electron Volt: A measure of the energy gained by
an electron falling through an electric field produced by one volt.
- Electronic Frontier Foundation: (EFF) A foundation that
addresses social & legal issues arising from the impact of computers on
- Electronic Mail: (E-Mail) An application
with which users can send information to other users with whom they share a
data communication connection.
- Electronics Industry
Association: (EIA) An organization responsible for establishing
communication signal characteristics.
- Electrostatic: Pertaining to
static electricity, or electricity at rest. An electric charge, for
- EMF: Electromotive force (voltage).
- EMI: See Electromagnetic Interference
- EMI/RFI: See Radio Frequency Interference
- Emulation: The
imitation of all or part of one device, terminal, or computer by another, so
that the imitating device accepts the same data, performs the same functions, &
appears to other network devices as if it were the imitated
- Encapsulate: A basic protocol layering technique. The
information from a higher level protocol (which may include both data &
headers) is carried as the data portion of lower-level protocol, which adds its
own header information. For example, IP datagrams are encapsulated in Data Link
- Encoding/Decoding: Organizing information into a format
suitable for transmission, & then reconverting it after transmission; for
pulse-code modulated voice transmission, the generation of digital signal to
represent quantized samples, & the subsequent reverse
- Encryption: The basis of network security. Encryption
encodes network packets to prevent anyone except the intended recipient from
accessing the data.
- End of Text: EXT
- End of
Transmission: (EOT) A control character in Data Link Control (DLC). EOT is
sent by a DTE to indicate conclusion of transmission.
- End of Transmission Block: (ETB) A control character in the
DLC, ETB indicates the end of an "Immediate" block.
- End-to-end: An
expression used in the networking environment to indicate communication between
source & destination nodes on a network system. End-to-end communication is
carried out by the transport layer of TCP/IP.
Small Device Interface: (ESDI) an Interface type for computer adapter &
- Enterprisewide Network: A Internetwork connecting
all sites of a single corporation worldwide.
Emulator High Level Language Applications Interface: (EEHLLAPI) An IBM API
subset of HLLAPI.
- EOT: See End of Transmission
- EPROM: See Erasable Programmable Read-Only Memory
Room: A room that serves the space needs for larger telecommunications
equipment. Note: These are often special purpose rooms. Equipment rooms are
connected to the backbone facility.
Programmable Read-Only Memory: (EPROM) A nonvolatile semiconductor PROM
that can be erased by exposing it to intense ultraviolet light for
- Erasable Storage: A storage device whose contents can be
modified, (e.g. Random Access Memory, or RAM), as contrasted with read-only
storage (e.g. Read-Only Memory, or ROM).
- Error: A term used to
describe signals with a rate or value below the accepted norms. An error may be
caused by mutilation of bits, loss of bits or character, or improper DLC (Data
Link Control) procedure.
- Error Condition: The discrepancy between the
sent data & the received data. Error condition may be caused by mutilation of
bits, loss of bits or characters, or improper use of DLC procedure.
Rate: A measure of data integrity, expressed as a fraction of corrupted
bits over transmission bits per second.
- ESCON: IBM’s “Planning for
Enterprise Systems Connection Links” provides information on fiber optic cable
types & environment for ESCON capable devices. ESCON is intended for use in a
mainframe environment rather than for local area networking or
- ESDI: See Enhanced Small Device
- Establishment Procedure: The ASCII term for initial
handshaking, a sequence in data transfer. During Establishment Procedure, the
two communicating DTE's may exchange identities & confirm that they are able to
- ETB: See End of Transmission
- Ethernet: A 10 Mbps network standard using CSMA/CD access.
It was developed by Xerox, DEC & Intel. See also Fast
- EtherTalk: AppleTalk protocol governing Ethernet
transmissions. Also the Apple computer Ethernet adapter &
- Ethertype: A 2 byte code indicating protocol type in an
Ethernet packet. ETX: (End of Text) A control character in the DLG. ETX
indicates the end of text information in a block.
- Even Parity: A
"dumb" terminal data-verification method in which each character must have an
even number of "1" bits.
- Expanded Memory: A PC's address memory
(above 1 Meg).
- EXT: End of Text
Binary Coded Decimal Interchange Code: (EBCDIC) An 8 bit character code
used primarily in IBM equipment; the code provides for 256 different bit
patterns; compare with ASCII.
- Extended Industry
Standard Architecture: (EISA) A 32 bit adaptation of the 8 & 16 bit buses
originally developed by IBM & now standard in almost all PC's that use Intel
8086, 80286 & 80386 microprocessors. The EISA bus is joint development of
COMPAQ & other PC manufactures.
- Extended Memory: A PC's address
memory (640K to 1 Meg.)
- Exterior Gateway Protocol:
(EGP) A protocol used to advertise the OP address of one networks system to
another. Each individual system must use EGP to advertise their reachability by
the routing system.
- External Storage Controller: A sub-unit in a
computer or attached to a computer that manages the movement of data between
the computer & the external storage device(s), such as, disk drives & tape